How severe is CVE-2020-1147?

CVE-2020-1147 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-1147?

CVE-2020-1147 affects the following packages: Microsoft.NETCore.App (NuGet), Microsoft.NETCore.App.Runtime.linux-arm (NuGet), Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet), Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet), Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet), Microsoft.NETCore.App.Runtime.linux-x64 (NuGet), Microsoft.NETCore.App.Runtime.osx-x64 (NuGet), Microsoft.NETCore.App.Runtime.rhel.6-x64 (NuGet), and 4 more. Ecosystems affected: NuGet.

How do I fix CVE-2020-1147?

Update Microsoft.NETCore.App to 2.1.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-1147 is resolved across your whole dependency graph.

How do I detect CVE-2020-1147 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.NETCore.App. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2020-1147 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2020-1147?

O3 pinpoints whether CVE-2020-1147 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2020-1147 actively exploited in the wild?

Yes. There are 8 known exploit references for CVE-2020-1147, including 2 documented proof-of-concept exploits on Exploit-DB and 6 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-1147?

CVE-2020-1147 has an EPSS (Exploit Prediction Scoring System) score of 94.2%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2020-1147 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-1147 (Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2020-1147 published, and has it been updated?

CVE-2020-1147 was published on July 14, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03

.NET NuGet

CVE-2020-1147

HIGH

.NET Framework, SharePoint Server, and Visual Studio Remote Code Execution Vulnerability

Also known asGHSA-g5vf-38cp-4px9

Published

Jul 14, 2020

Updated

Jul 8, 2026

Affected

12 pkgs

Patched

12 / 12

Exploits

8 known

EPSS Exploitation Probability

via FIRST.org ↗

94.2%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

12 pkgs affected

.NETMicrosoft.NETCore.App.NETMicrosoft.NETCore.App.Runtime.linux-arm.NETMicrosoft.NETCore.App.Runtime.linux-arm64.NETMicrosoft.NETCore.App.Runtime.linux-musl-arm64.NETMicrosoft.NETCore.App.Runtime.linux-musl-x64.NETMicrosoft.NETCore.App.Runtime.linux-x64.NETMicrosoft.NETCore.App.Runtime.osx-x64.NETMicrosoft.NETCore.App.Runtime.rhel.6-x64+4 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

A remote code execution vulnerability exists in .NET Framework, Microsoft SharePoint, and Visual Studio when the software fails to check the source markup of XML file input, aka '.NET Framework, SharePoint Server, and Visual Studio Remote Code Execution Vulnerability'.

Affected Packages

12 total 12 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Microsoft.NETCore.App`	≥ 2.1.0&&< 2.1.20	2.1.20
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-arm`	≥ 3.1.0&&< 3.1.6	3.1.6
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-arm64`	≥ 3.1.0&&< 3.1.6	3.1.6
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-musl-arm64`	≥ 3.1.0&&< 3.1.6	3.1.6
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-musl-x64`	≥ 3.1.0&&< 3.1.6	3.1.6
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-x64`	≥ 3.1.0&&< 3.1.6	3.1.6

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-48747webappsaspx

Microsoft SharePoint Server 2019 - Remote Code Execution

by West Shepherd · Aug 17, 2020

Exploit-DB Source

EDB-50151webappsaspx

Microsoft SharePoint Server 2019 - Remote Code Execution (2)

by Podalirius · Jul 23, 2021

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.NETCore.App. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Microsoft.NETCore.App to 2.1.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-1147 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2020-1147 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2020-1147. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-1147 in your dependencies?

O3 detects CVE-2020-1147 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works